The subject invention is directed toward the valve art and, more particularly, to an improved ball valve.
The invention is especially suited for small, compact multi-service ball valves; however, as will become apparent, the invention could be incorporated in valves of many sizes or in special service valves. The manufacture of ball valve bodies or housings often requires a significant amount of relatively complex machining whether the bodies are formed from bar stock, forged or cast. To simplify the machining without seriously affecting the performance of the valves, the housings have often been designed as multi-part assemblies having separate bonnet components and threadedly attached end pieces. In addition, to simplify the internal machining the valves have often been provided with separate inserts or sleeve-like members for carrying the ball seal and body seal elements. Consequently, the resulting valves have often been relatively complex and/or a compromise in design.
The above discussed manufacturing and design problems are amplified for smaller sized ball valves such as those for process and instrumentation purposes. Also, the designs available often do not assure that the stems, seat and/or balls will be blowout proof.